fstab

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The fstab (file system table) file (/etc/fstab) is a configuration file that is used to configure how and where the main filesystems are mounted, especially at boot time.

Syntax

Each line of /etc/fstab contains the necessary settings to mount one partition, drive or network share. The line has six columns, separated by whitespaces or tabs. The columns are as follows:

  1. The device file, UUID or label or other means of locating the partition or data source.
  2. The mount point, where the data is to be attached to the filesystem.
  3. The filesystem type.
  4. Options, including if the filesystem should be mounted at boot.
  5. Adjusts the archiving schedule for the partition (used by app-arch/dump). 0 disables, 1 enables the feature.
  6. Controls the order in which fsck checks the device/partition for errors at boot time. The root device should be 1. Other partitions should be either 2 (to check after root) or 0 (to disable checking for that partition altogether).

An example for the root device:

File/etc/fstab

/dev/sda1   /   ext4   defaults   0   1

UUIDs and labels

Instead of device files you can use a UUID:

File/etc/fstabUsing a UUID for the root partition

UUID="339df6e7-91a8-4cf9-a43f-7f7b3db533c6"   /   ext4   defaults   0   1

Otherwise you can use a label:

File/etc/fstabUsing a label for the root partition

LABEL="Gentoo"   /   ext4   defaults   0   1

Please read this for details on how to retrieve UUIDs and labels.

Services

The following OpenRC services read the fstab to mount or manage the filesystems.

  • localmount- Mount disks and swap according to fstab.
  • netmount - Mount network shares according to fstab.
  • fsck - Check and repair filesystems according to fstab.
  • root - Mount the root filesystem read/write.

These services supplement the fstab, if the filesystems are not explicit stated:

  • sysfs - Mount the /sys filesystem.
  • devfs - Mount system critical filesystems in /dev.

Check that they are enabled to start at boot time:

root # rc-update show

See also